Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7 DOI 10.1186/s40781-016-0085-5
REVIEW
Open Access
Recent advances in canola meal utilization in swine nutrition G. Mejicanos1, N. Sanjayan1, I. H. Kim2* and C. M. Nyachoti1
Abstract Canola meal is derived from the crushing of canola seed for oil extraction. Although it has been used in swine diets for a long time, its inclusion levels have been limited due to concerns regarding its nutritive value primarily arising from results of early studies showing negative effects of dietary canola meal inclusion in swine diets. Such effects were attributable to the presence of anti-nutritional factors (ANF; notably glucosinolates) in canola meal. However, due to advances in genetic improvements of canola that have led to production of cultivars with significantly lower ANF content and improved processing procedures, canola meal with a superior nutritive value for non-ruminant animals is now available. Therefore, the aim of this paper is to review the recent studies in the use of canola meal as feedstuff for swine, the factors influencing its use and the strategies to overcome them. First a historical overview of the development of canola is provided. Keywords: Canola meal, Nutritive value, Pigs
Background Canola is an offspring of rapeseed which belongs to the cabbage family or Brassicas. The genus Brassica also contains plants such as cabbage, radish, kale, mustard and cauliflower [10]. Rapeseed oil contains around 2545 % erucic acid whereas the meal contains about 110150 μmoles/g of aliphatic glucosinolates [12]. Rapeseed was cultivated more than 3000 years ago in India and 2000 years ago in China and Japan. The development of steam power resulted in better industrial acceptance of rapeseed. It was introduced to Canada between 1936 and early 1940s as a method of diversifying crop production, especially for the Prairie Provinces [10, 30, 69]. The fuel shortage caused by World War II led to the increased production of rapeseed. However, with the switch to diesel engines, and also the ban of the use of rapeseed for human consumption by the USA in 1956, the demand for rapeseed declined [95]. Rapeseed contains high levels of glucosinolates, which can be hydrolyzed by the enzyme myrosinase to release products with goitrogenic effects that interfere with iodine metabolism and therefore affect the functioning of * Correspondence: [email protected] 2 Department of Animal Resource & Science, Dankook University, Cheonan, Choognam, South Korea Full list of author information is available at the end of the article
the thyroid gland and consequently animal performance [53]. To address these effects, plant breeders worked to develop rapeseed cultivars with low glucosinolate content in the meal and low erucic acid content in rapeseed oil. The first low-erucic acid rapeseed was developed in Canada by Dr. Baldour R. Stefansson of the University of Manitoba, who has been referred to as “The father of canola” because of his contribution to the development of low-erucic acid type rapeseed. In early 1960s, he surveyed over 4000 lines of rapeseed from all over the world and identified low-erucic acid lines which were then used in the breeding programs at the University of Manitoba and also by Dr. Keith Downey at the Agriculture Canada Research Station in Saskatoon. In 1968, the first low-erucic acid cultivars Tanka, Target and Turret were released and produced in Canada [10, 85]. By 1974, Dr. Stefansson released the first double zero rapeseed cv. Tower [10]. In 1979, all double low cultivars produced in Canada were named as Canola [10]; the name of canola is a contraction of Canada and “ola” that refers to “oil low acid” [22]. The name was used to differentiate canola from the high-glucosinolate, high-erucic acid rapeseed. The name canola refers to “Seeds of the genus Brassica (Brassica napus, Brassica rapa or Brassica juncea) from which the oil shall contain less than 2 % erucic acid in its fatty acid
© 2016 Mejicanos et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Page 2 of 13
Fig. 1 Effect of phytase supplementation on standardized total tract of digestibility of phosphorus in two types of canola meal fed to growing pigs (Adapted from [3])
profile and the solid component shall contain less than 30 micromoles of any one or any mixture of 3-butenyl glucosinolate, 4-pentenyl glucosinolate, 2-hydroxy-3 butenyl glucosinolate, and 2-hydroxy-4-pentenyl glucosinolate per gram of air-dry, oil-free solid” [22]. In the international community canola is also known as “double zero”, “Zero-zero” or “double low” rapeseed. Canola is currently the leading oil seed crop in Canada with an annual production of over 15 million tonnes [23] and the importance of its meal as a protein supplement is second only to soybean meal. During crushing, canola seed yield 42 % of oil, which is used as vegetable oil for human consumption and 58 % meal, which is
used as a protein source in animal feed [94]. The aim of this article is to review the recent studies in the use of canola meal as feedstuff for swine, the factors influencing its use and the strategies to overcome them. Chemical and nutritive value of canola meal
Earlier studies with different types of canola demonstrated that black and yellow seeds differ significantly in their chemical and nutritive composition, particularly in the contents of oil, crude protein (CP) and fiber [56, 82]. As can be seen from Table 1, CP content of three different types of canola meal (CM) differed significantly, with B. juncea showing the highest protein content of 42.3 %,
Table 1 Chemical composition of meals derived from black- or yellow-seeded B. napus canola and canola quality B. juncea (% as is basis) a B. napus “black”
Component
B. napus “yellow”
B. juncea “yellow”
Crude protein
36.9
41.0
42.3
Fat
3.8
3.7
3.4
Ash
7.1
7.9
6.6
Sucrose
6.3
8.4
7.6
Acid detergent fiber
17.0
12.0
9.7
Neutral detergent fiber
23.6
16.4
15.9
Non-starch polysaccharides
17.0
21.1
19.4
Total fiber %
30.1
27.1
25.5
Lignin and polyphenols
10.3
2.7
4.0
Dietary fiber fractions
Glycoprotein Phosphorus (P)
3.2
2.1
1.25
1.04
Phytate P
0.56
0.80
0.58
Non-phytate P
0.39
0.44
0.46
Calcium Glucosinolates, μmol/g a
2.8 0.95
b
0.67
0.55
0.76
9.2
13.5
12.2
Adapted from Mejicanos [56]; bIncludes gluconapin, glucobrassicanapin, progoitrin, gluconapoleiferin, gluconasturtin, glucobrassicin, and 4-hydroxyglucobrassicin
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Page 3 of 13
followed by 41.0 % in yellow seeded B. napus and 36.9 % in B. napus black (as is basis). Furthermore, distinctive differences can be observed between cultivars in terms of NDF, ADF, NSPs, lignin and pholyphenols, phosphorus, etc. The oil extraction process of the seeds would also affect the CP content with oil-expelled CM containing 35.2 %, while pre-press solvent extracted meal containing 37.5 % (as-fed basis) [65]. Other factors that affect the protein content of CM are the environmental conditions during the growing season. Tipples [92] found that over the 10 years, from 1978 to 1987, the CP content of CM ranged from 36 to 41 %. Bell et al. [14] found that location is another factor that can affect mineral content of B. napus, B. rapa and B. juncea.
Therefore, both meals complement each other when used in rations for livestock and poultry [40]. It has been reported that there is a negative relationship between protein and dietary fiber content of meals derived from black and yellow seeded B. napus canola [82], such differences will affect the percentage of AA content of the different cultivars. Removing fiber from the meal would translate into fractions with higher CP and AA content. For example, Mejicanos et al. [57]. evaluated the nutritive value of dehulled CM and observed that with the reduction of fiber, the CP and AA contents were increased. Table 2 shows the AA composition of meals derived from black and yellow B. napus, and yellow B. juncea and the corresponding dehulled fraction 1 produced by sieving; e.g. lysine increased from 2.02 to 2.26 %, from 1.91 to 2.34 and from 1.95 to 2.29 % for B. napus black, B. napus yellow and B. juncea meal respectively. Methionine increased from 0.68 to 0.81, 0.63 to 0.71 and 0.66 to 0.83 % for B. napus black, yellow and B. juncea, respectively. Conditions in the processing plants also affected the quality of CM, and in that regard Adewole et al. [2] reported significant variations in AA content (P < 0.05) of CM from different processing plants across Canada; e.g. arginine, lysine, methionine, and threonine averaged 2.22, 1.78, 0.52, and 1.07 %, respectively, and ranged from 2.00 to 2.44 % for arginine, 1.61 to 1.96 % for lysine, 0.45 to 0.63 % for methionine, and 0.94 to 1.34 % for threonine. The study also
Protein and amino acid source
It has been documented that the meal from yellow seeded B. juncea and B. napus yellow contains more CP (DM basis) in comparison with the conventional B. napus black; 43.4 and 47.2 vs. 41.1 % [93]. CM contains a well-balanced amino acid (AA) profile and when compared to soybean meal (SBM), it contains less lysine, but more sulphur AA (i.e. methionine and cysteine) ([67]a). CM contains approximately 2 % methionine as a percent of total protein, while SBM has 1.5 %. However, CM has lower amount of lysine compared to SBM. It also contains 10 % lower available lysine compared to SBM [76].
Table 2 Amino acid composition of conventional B. napus “black” canola meal, B. napus yellow meal and canola-type B. juncea yellow mustard meal, and their corresponding dehulled fraction 1 produced by sieving (%, as-is basis)a B. napus “black”
B. napus “yellow”
B. juncea “yellow”
Amino acid
Parent meal
Dehulled fraction 1
Parent meal
Dehulled fraction 1
Parent meal
Dehulled fraction 1
Alanine
1.49
1.76
1.56
1.89
1.72
2.05
Arginine
2.28
2.77
2.08
2.63
2.85
3.60
Aspartate
2.62
3.01
2.30
2.89
3.34
3.87
Cysteine
0.80
0.92
0.91
0.94
0.70
0.85
Glutamine
6.60
7.81
5.91
7.44
7.26
8.49
Glycine
1.85
2.19
1.45
1.85
2.16
2.56
Histidine
1.18
1.37
1.10
1.35
1.31
1.51
Isoleucine
1.21
1.46
1.06
1.34
1.21
1.81
Leucine
2.43
2.92
2.31
2.86
2.76
3.52
Lysine
2.02
2.26
1.91
2.34
1.95
2.29
Methionine
0.68
0.81
0.63
0.71
0.66
0.83
Phenylalanine
1.40
1.69
1.31
1.61
1.53
1.98
Proline
2.54
2.89
2.44
2.85
2.77
2.93
Serine
1.69
1.93
1.63
1.99
1.94
2.18
Threonine
1.62
1.85
1.33
1.66
1.82
2.14
Tyrosine
0.93
1.11
0.84
1.06
1.05
1.34
Valine
1.66
1.95
1.54
1.90
1.62
2.35
a
Adapted from Mejicanos [56]
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Table 3 Standardized ileal digestibility (%) of amino acids in canola meal fed to growing pigs Item
Expeller extracted
Solvent extracted
[96]
[79]
[50]
[96]
[75]
[50]
Histidine
84.7
81.7
83.8
78.1
87.1
82.0
Isoleucine
85.4
74.3
77.7
78.1
79.7
75.9
Leucine
87.2
78.8
81.6
79
80.3
79.3
Essential
Lysine
70.7
73.2
74.7
66.6
78.9
70.6
Methionine
87.4
83.9
87.1
84.1
84.2
84.5
Phenylalanine
90.4
78.0
81.1
90.4
70.8
78.2
Threonine
79.5
67.6
74.0
72.1
77.1
73.0
Tryptophan
83.9
83.4
83.8
70.5
75.9
76.7
78.5
74.4
Arginine
91.7
83.1
89.4
86.2
90.3
86.3
Cysteine
80.1
72.7
72.9
79.3
79.8
73.2
Tyrosine
98.2
75.1
75.6
93.3
78.7
74.7
Alanine
85.1
72.1
80.2
76.3
78.2
75.8
Aspartate
82.2
72.0
77.8
75
77.8
71.8
Glutamate
91.6
84.3
85.9
86.9
88.3
83.4
Glycine
86.2
63.6
78.6
82.2
76.5
78.1
Serine
76.7
70.6
76.7
76.7
80.7
75.7
Valine
82.6
Conditionally Essential
Non-essential
Woyengo et al., [96]; Seneviratne et al., [79]; Maison and Stein [50]; Sanjayan et al., [75]
reported that pelleting significantly reduced the AA content of the meal. Results reported by Adewole et al. [2] indicates that standardized Ileal digestibility (SID) of arginine, lysine, methionine and threonine averaged 87.5, 78.8, 85.4 and 74.8 %, respectively. Table 3 shows SID values of solvent extracted CM (SECM) and expeller extracted CM (EECM) fed to growing pigs as reported by Woyengo et al. [96], Maison and Stein [50], Seneviratne et al. [79] and Sanjayan et al. [75]. Energy source
One of the main factors that limit the nutritive value of CM is its low digestibility of energy which is a reflection of its high crude fibre content [88]. Compared to soybean, canola contains a higher amount of oil with many cultivars containing between 40 and 45 % oil on a dry matter basis [32]. The energy content of CM can differ between samples obtained from different crushing plants due to the oil extraction process, i. e. expelled CM contains residual oil at average levels of 9.7 %, compared to 3.2 % for the pre-press solvent extracted meal [65]. The oil content of the meal from the pre-press solvent extraction process would also be affected by the amount of gums added back to the meal following oil refining. As
Page 4 of 13
indicated by Bell [12], gums may contain about 50 % of canola oil and such oil is expected to increase the ME values of the meal. Theodoridou and Yu [91] evaluated the effect of processing conditions on the nutritive value of canola meal and reported significant differences between CM from black- and yellow-seeded B. napus for the basic nutrients, except ash. The differences between yellow and black canola included NDF, ADF, CP, and condensed tannins. Yellow-seeded CM showed higher values for CP, total digestible CP, and lower fiber content [12, 82]. The differences between CM from different cultivars of canola are illustrated in Table 1. Sucrose content for yellow seeded B. napus was higher, and averaged 8.4 %, while the mean values for B. juncea and B. napus black were 6.3 and 7.6 %, respectively. In the case of nonstarch polysaccharides, yellow-seeded B. napus reported higher values and averaged 21.1 %, whereas values for B. juncea and B. napus black averaged 19.4 and 17.0 %, respectively. Total dietary fiber was lower in B. juncea CM, and averaged 25.5 %; 27.1 % for yellow-seeded B. napus whereas B. napus black had 30.1 %. In the case of expelled meal which contains an average 10.0 % of ether extract, the values reported for GE, DE, ME and NE averaged 4873, 3779, 3540 and 2351 kcal/kg, respectively. For pre-press solvent extracted CM, which contains less ether extract (3.2 % on average), the values average 4332, 3273, 3013 and 1890 kcal/kg, respectively [65]; whereas the values for yellow seeded B. napus averaged 3.965, 3248, 3009, and 2102 kcal/kg, respectively; the values for yellow B. juncea averaged 4037, 3392, 3224 and 2340 kcal/kg, respectively [38]. Dehulling of canola can result in a higher energy meal, as shown by research on tail end dehulling of pre-press solvent extracted CM from black and yellow seeded B. napus and canola quality B. juncea; dehulling resulted in low fiber high protein fractions Fine 1 and Fine 2. Compared to their parent meals, the content of total dietary fiber in the fractions decreased from 30.1 to 21.4 and 26.7 % for conventional CM, from 25.5 to 15.3 and 18.7 for yellow-seeded CM, and from 27.1 to 21.6 and 23.4 for B. juncea meal, respectively [56]. The complete removal of the hulls of canola would result in high protein-high energy meal with 47.8 % protein, 10.8 % NDF, 6.6 ADF. [25]. Vitamins and minerals source
Canola meal is a rich source of most of the minerals [12]. Compared to soybean meal, CM has relatively high amounts of Ca, P, S, Mg, Mn and Se, but K and Cu contents are lower Table 4 shows the chemical composition of CM compared to soybean meal [12, 40, 80]; such values are in accordance with National Research Council. Nutrient requirements of swine. 11th Rev. Ed et al.
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Table 4 Chemical composition of canola meal compared to soybean meal Components
Canola meal
Soybean meal
Dry matter, %
90.0
90.0
Crude protein, %
36.5
45.6
Ether extract, %
3.6
1.3
Gross energy, MJ/kg
18.6
20.1
Starch
2.5
0.7
Sucrose
6.0
6.2
Sugar
7.7
6.9
Oligosaccharide
2.5
5.3
Crude fibre
11.6
5.4
Non-starch polysaccharide
18.0
17.8
Neutral detergent fibre
26.0
12.0
Acid detergent fibre
18.2
7.5
Total dietary fibre
31.7
21.8
Arginine
2.04
3.23
Lysine
2.00
2.86
Threonine
1.57
1.74
Methionine
0.74
0.65
Cysteine
0.85
0.67
Tryptophan
0.48
0.64
Calcium
0.7
0.3
Phosphorus
1.2
0.7
Magnesium
0.6
0.3
Sodium
0.08
0.01
Potassium
1.29
2.0
1.0
0.3
Carbohydrates, %
Fibre, %
Amino acids, %
Minerals, %
Vitamins, mg/kg Biotin Folic acid
2.3
1.3
Niacin
169.5
29.0
Pantothenic acid
9.5
16.0
Riboflavin
3.7
2.9
Thiamine
5.2
4.5
Bell [12], Simbaya [80], Khajali and Slominski [40]
[65], However, the presence of phytic acid and high fibre in the meal reduces the availability of most of the minerals. Although the availability of most of the minerals is low in CM, it has high amounts of available Ca, Mg and P compared to soybean meal as shown in Table 4. Canola meal contains considerably high amount of phytatebound phosphorus in proportion to total phosphorus and which ranges from 36 % to over 70 % [40]. Due to
Page 5 of 13
this reason bioavailability of phosphorus has been estimated to be around 30 to 50 % of the total phosphorus in CM [35]. Compared to SBM, CM is a richer source of vitamins such as biotin, niacin, choline, thiamin, Vitamin B6 and niacin. However, pantothenic acid content is lower in CM [28, 65]. Factors affecting feeding and nutritive value of canola meal for swine
There are several factors that limit the use of CM, especially in monogastric animal nutrition. When compared with SBM, CM contains higher contents of dietary fiber, glucosinolates, sinapine, phytic acid, phenolic components such as tannins, lower metabolizable energy, with less consistent AA digestibility and less than optimum electrolyte balance due to high sulfur and low potassium contents [40]. Among these, fibre, glucosinolates, phytic acid and and sinapine are considered to be the main antinutritional factors in CM. Fibre
Fiber content in CM is 3 times higher than SBM [12], which is the result of a large proportion of hulls relative to seed size. The hull represents 16.8 % to 21.2 % of the seed mass [25], but increases to about 30 % of the meal weight after oil extraction, which is the main reservoir for non-starch polysaccharides (NSP) and lignin. Low levels of DE and ME in CM is due to the high level of fiber [12]. High protein soy and 44 % soy with hulls added back contain around 4 % and 7.5 % fibre, respectively, whereas CM has more than 10 % crude fibre [32]. CM contains cellulose (4-6 %), non-cellulosic polysaccharide (13-16 %), lignin and polyphenols (5-8 %) and proteins and minerals associated with the fibre fraction as the major fibre components [81]. Previous studies demonstrated that yellow-seeded meal has low amount of fibre compared to black-seeded meal. For instance, ADF and NDF contents of B. juncea (9.7 % and 15.9 %) are lower compared to those (17.0 % and 23.6 %) of B. napus black as shown in Table 1 [56]. Fibre mainly contains NSP, lignin associated with polyphenols, polyphenol glycoproteins and minerals associated with fibre [80]. Non-starch polysaccharide components of CM are shown in Table 5. Pectic polysaccharidies are present in CM as a non-cellulosic polysaccharide, which is indicated by the presence of uronic acid [81]. Arabinose, xylose, galactose and rhamnose are the main components of galacturonic acid. Part of the arabinose and galactose were derived from arabinan and/or arabinogalactan. Presence of xylose indicates the presence of xylan and xyloglucans. Xyloglucans contain xylose, glucose, galactose and fucose [81]. Cellulose, arabinose, arabinogalactan and pectins are the major NSP components in CM [41,
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Table 5 Non-starch polysaccharides components of canola meal (mg/g) Black B. napus
Yellow B. juncea
Yellow B. napus
Rhamnose
1.2
1.2
1.0
Fucose
1.0
0.8
0.8
Component
Arabinose
22.9
24.1
24.8
Xylose
9.1
7.5
10.3
Mannose
2.6
1.5
2.1
Galactose
7.9
7.7
8.8
Glucose
29.6
27.6
27.2
Uronic acids
26.6
30.4
26.5
Adapted from [82]
59, 81]. In the study by Meng and Slominski [58] it was reported that CM contained 174.5 mg/g total NSP of which 14.3 mg/g was water soluble. Glucosinolates
Glucosinolates (GLS) are sulphur-containing secondary plant metabolites found mainly in the order Capparales known also as Brassicales, which contain plants of the family Brassicaceae that includes the genus Brassica (rapeseed, mustard, and cabbage) [27, 40]. Intact GLS do not cause any harmful effects to animals, however, the break down products of GLS either by enzyme myrosinase or by non-enzymatic factors such as heat, low pH, anatomical and physiological structure of the gastrointestinal tract, digesta transit time and microbial activity cause harmful effects to animals [12]. Depending on the nature of GLS, reaction condition and concentration, the break down products- thiocyanate, isothiocyanate, oxazolidinethione (goitrin) and nitriles may be formed and impair not only feed intake (due to their bitter taste) and growth performance but also affect thyroid function by inhibiting thyroid hormone production and impair liver and kidney function [12, 20, 61]. Previous studies show that growing pigs can tolerate a maximum of 2.02.5 μmol/g of glucosinolates in the diet [12, 74, 77].
Page 6 of 13
Glucosinolates are considered an anti-nutritional factor present in CM. Rapeseed meal contained 110150 μmol/g of GLS [12]. However, through plant breeding techniques new canola varieties have been developed with low level of GLS (
REVIEW
Open Access
Recent advances in canola meal utilization in swine nutrition G. Mejicanos1, N. Sanjayan1, I. H. Kim2* and C. M. Nyachoti1
Abstract Canola meal is derived from the crushing of canola seed for oil extraction. Although it has been used in swine diets for a long time, its inclusion levels have been limited due to concerns regarding its nutritive value primarily arising from results of early studies showing negative effects of dietary canola meal inclusion in swine diets. Such effects were attributable to the presence of anti-nutritional factors (ANF; notably glucosinolates) in canola meal. However, due to advances in genetic improvements of canola that have led to production of cultivars with significantly lower ANF content and improved processing procedures, canola meal with a superior nutritive value for non-ruminant animals is now available. Therefore, the aim of this paper is to review the recent studies in the use of canola meal as feedstuff for swine, the factors influencing its use and the strategies to overcome them. First a historical overview of the development of canola is provided. Keywords: Canola meal, Nutritive value, Pigs
Background Canola is an offspring of rapeseed which belongs to the cabbage family or Brassicas. The genus Brassica also contains plants such as cabbage, radish, kale, mustard and cauliflower [10]. Rapeseed oil contains around 2545 % erucic acid whereas the meal contains about 110150 μmoles/g of aliphatic glucosinolates [12]. Rapeseed was cultivated more than 3000 years ago in India and 2000 years ago in China and Japan. The development of steam power resulted in better industrial acceptance of rapeseed. It was introduced to Canada between 1936 and early 1940s as a method of diversifying crop production, especially for the Prairie Provinces [10, 30, 69]. The fuel shortage caused by World War II led to the increased production of rapeseed. However, with the switch to diesel engines, and also the ban of the use of rapeseed for human consumption by the USA in 1956, the demand for rapeseed declined [95]. Rapeseed contains high levels of glucosinolates, which can be hydrolyzed by the enzyme myrosinase to release products with goitrogenic effects that interfere with iodine metabolism and therefore affect the functioning of * Correspondence: [email protected] 2 Department of Animal Resource & Science, Dankook University, Cheonan, Choognam, South Korea Full list of author information is available at the end of the article
the thyroid gland and consequently animal performance [53]. To address these effects, plant breeders worked to develop rapeseed cultivars with low glucosinolate content in the meal and low erucic acid content in rapeseed oil. The first low-erucic acid rapeseed was developed in Canada by Dr. Baldour R. Stefansson of the University of Manitoba, who has been referred to as “The father of canola” because of his contribution to the development of low-erucic acid type rapeseed. In early 1960s, he surveyed over 4000 lines of rapeseed from all over the world and identified low-erucic acid lines which were then used in the breeding programs at the University of Manitoba and also by Dr. Keith Downey at the Agriculture Canada Research Station in Saskatoon. In 1968, the first low-erucic acid cultivars Tanka, Target and Turret were released and produced in Canada [10, 85]. By 1974, Dr. Stefansson released the first double zero rapeseed cv. Tower [10]. In 1979, all double low cultivars produced in Canada were named as Canola [10]; the name of canola is a contraction of Canada and “ola” that refers to “oil low acid” [22]. The name was used to differentiate canola from the high-glucosinolate, high-erucic acid rapeseed. The name canola refers to “Seeds of the genus Brassica (Brassica napus, Brassica rapa or Brassica juncea) from which the oil shall contain less than 2 % erucic acid in its fatty acid
© 2016 Mejicanos et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Page 2 of 13
Fig. 1 Effect of phytase supplementation on standardized total tract of digestibility of phosphorus in two types of canola meal fed to growing pigs (Adapted from [3])
profile and the solid component shall contain less than 30 micromoles of any one or any mixture of 3-butenyl glucosinolate, 4-pentenyl glucosinolate, 2-hydroxy-3 butenyl glucosinolate, and 2-hydroxy-4-pentenyl glucosinolate per gram of air-dry, oil-free solid” [22]. In the international community canola is also known as “double zero”, “Zero-zero” or “double low” rapeseed. Canola is currently the leading oil seed crop in Canada with an annual production of over 15 million tonnes [23] and the importance of its meal as a protein supplement is second only to soybean meal. During crushing, canola seed yield 42 % of oil, which is used as vegetable oil for human consumption and 58 % meal, which is
used as a protein source in animal feed [94]. The aim of this article is to review the recent studies in the use of canola meal as feedstuff for swine, the factors influencing its use and the strategies to overcome them. Chemical and nutritive value of canola meal
Earlier studies with different types of canola demonstrated that black and yellow seeds differ significantly in their chemical and nutritive composition, particularly in the contents of oil, crude protein (CP) and fiber [56, 82]. As can be seen from Table 1, CP content of three different types of canola meal (CM) differed significantly, with B. juncea showing the highest protein content of 42.3 %,
Table 1 Chemical composition of meals derived from black- or yellow-seeded B. napus canola and canola quality B. juncea (% as is basis) a B. napus “black”
Component
B. napus “yellow”
B. juncea “yellow”
Crude protein
36.9
41.0
42.3
Fat
3.8
3.7
3.4
Ash
7.1
7.9
6.6
Sucrose
6.3
8.4
7.6
Acid detergent fiber
17.0
12.0
9.7
Neutral detergent fiber
23.6
16.4
15.9
Non-starch polysaccharides
17.0
21.1
19.4
Total fiber %
30.1
27.1
25.5
Lignin and polyphenols
10.3
2.7
4.0
Dietary fiber fractions
Glycoprotein Phosphorus (P)
3.2
2.1
1.25
1.04
Phytate P
0.56
0.80
0.58
Non-phytate P
0.39
0.44
0.46
Calcium Glucosinolates, μmol/g a
2.8 0.95
b
0.67
0.55
0.76
9.2
13.5
12.2
Adapted from Mejicanos [56]; bIncludes gluconapin, glucobrassicanapin, progoitrin, gluconapoleiferin, gluconasturtin, glucobrassicin, and 4-hydroxyglucobrassicin
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Page 3 of 13
followed by 41.0 % in yellow seeded B. napus and 36.9 % in B. napus black (as is basis). Furthermore, distinctive differences can be observed between cultivars in terms of NDF, ADF, NSPs, lignin and pholyphenols, phosphorus, etc. The oil extraction process of the seeds would also affect the CP content with oil-expelled CM containing 35.2 %, while pre-press solvent extracted meal containing 37.5 % (as-fed basis) [65]. Other factors that affect the protein content of CM are the environmental conditions during the growing season. Tipples [92] found that over the 10 years, from 1978 to 1987, the CP content of CM ranged from 36 to 41 %. Bell et al. [14] found that location is another factor that can affect mineral content of B. napus, B. rapa and B. juncea.
Therefore, both meals complement each other when used in rations for livestock and poultry [40]. It has been reported that there is a negative relationship between protein and dietary fiber content of meals derived from black and yellow seeded B. napus canola [82], such differences will affect the percentage of AA content of the different cultivars. Removing fiber from the meal would translate into fractions with higher CP and AA content. For example, Mejicanos et al. [57]. evaluated the nutritive value of dehulled CM and observed that with the reduction of fiber, the CP and AA contents were increased. Table 2 shows the AA composition of meals derived from black and yellow B. napus, and yellow B. juncea and the corresponding dehulled fraction 1 produced by sieving; e.g. lysine increased from 2.02 to 2.26 %, from 1.91 to 2.34 and from 1.95 to 2.29 % for B. napus black, B. napus yellow and B. juncea meal respectively. Methionine increased from 0.68 to 0.81, 0.63 to 0.71 and 0.66 to 0.83 % for B. napus black, yellow and B. juncea, respectively. Conditions in the processing plants also affected the quality of CM, and in that regard Adewole et al. [2] reported significant variations in AA content (P < 0.05) of CM from different processing plants across Canada; e.g. arginine, lysine, methionine, and threonine averaged 2.22, 1.78, 0.52, and 1.07 %, respectively, and ranged from 2.00 to 2.44 % for arginine, 1.61 to 1.96 % for lysine, 0.45 to 0.63 % for methionine, and 0.94 to 1.34 % for threonine. The study also
Protein and amino acid source
It has been documented that the meal from yellow seeded B. juncea and B. napus yellow contains more CP (DM basis) in comparison with the conventional B. napus black; 43.4 and 47.2 vs. 41.1 % [93]. CM contains a well-balanced amino acid (AA) profile and when compared to soybean meal (SBM), it contains less lysine, but more sulphur AA (i.e. methionine and cysteine) ([67]a). CM contains approximately 2 % methionine as a percent of total protein, while SBM has 1.5 %. However, CM has lower amount of lysine compared to SBM. It also contains 10 % lower available lysine compared to SBM [76].
Table 2 Amino acid composition of conventional B. napus “black” canola meal, B. napus yellow meal and canola-type B. juncea yellow mustard meal, and their corresponding dehulled fraction 1 produced by sieving (%, as-is basis)a B. napus “black”
B. napus “yellow”
B. juncea “yellow”
Amino acid
Parent meal
Dehulled fraction 1
Parent meal
Dehulled fraction 1
Parent meal
Dehulled fraction 1
Alanine
1.49
1.76
1.56
1.89
1.72
2.05
Arginine
2.28
2.77
2.08
2.63
2.85
3.60
Aspartate
2.62
3.01
2.30
2.89
3.34
3.87
Cysteine
0.80
0.92
0.91
0.94
0.70
0.85
Glutamine
6.60
7.81
5.91
7.44
7.26
8.49
Glycine
1.85
2.19
1.45
1.85
2.16
2.56
Histidine
1.18
1.37
1.10
1.35
1.31
1.51
Isoleucine
1.21
1.46
1.06
1.34
1.21
1.81
Leucine
2.43
2.92
2.31
2.86
2.76
3.52
Lysine
2.02
2.26
1.91
2.34
1.95
2.29
Methionine
0.68
0.81
0.63
0.71
0.66
0.83
Phenylalanine
1.40
1.69
1.31
1.61
1.53
1.98
Proline
2.54
2.89
2.44
2.85
2.77
2.93
Serine
1.69
1.93
1.63
1.99
1.94
2.18
Threonine
1.62
1.85
1.33
1.66
1.82
2.14
Tyrosine
0.93
1.11
0.84
1.06
1.05
1.34
Valine
1.66
1.95
1.54
1.90
1.62
2.35
a
Adapted from Mejicanos [56]
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Table 3 Standardized ileal digestibility (%) of amino acids in canola meal fed to growing pigs Item
Expeller extracted
Solvent extracted
[96]
[79]
[50]
[96]
[75]
[50]
Histidine
84.7
81.7
83.8
78.1
87.1
82.0
Isoleucine
85.4
74.3
77.7
78.1
79.7
75.9
Leucine
87.2
78.8
81.6
79
80.3
79.3
Essential
Lysine
70.7
73.2
74.7
66.6
78.9
70.6
Methionine
87.4
83.9
87.1
84.1
84.2
84.5
Phenylalanine
90.4
78.0
81.1
90.4
70.8
78.2
Threonine
79.5
67.6
74.0
72.1
77.1
73.0
Tryptophan
83.9
83.4
83.8
70.5
75.9
76.7
78.5
74.4
Arginine
91.7
83.1
89.4
86.2
90.3
86.3
Cysteine
80.1
72.7
72.9
79.3
79.8
73.2
Tyrosine
98.2
75.1
75.6
93.3
78.7
74.7
Alanine
85.1
72.1
80.2
76.3
78.2
75.8
Aspartate
82.2
72.0
77.8
75
77.8
71.8
Glutamate
91.6
84.3
85.9
86.9
88.3
83.4
Glycine
86.2
63.6
78.6
82.2
76.5
78.1
Serine
76.7
70.6
76.7
76.7
80.7
75.7
Valine
82.6
Conditionally Essential
Non-essential
Woyengo et al., [96]; Seneviratne et al., [79]; Maison and Stein [50]; Sanjayan et al., [75]
reported that pelleting significantly reduced the AA content of the meal. Results reported by Adewole et al. [2] indicates that standardized Ileal digestibility (SID) of arginine, lysine, methionine and threonine averaged 87.5, 78.8, 85.4 and 74.8 %, respectively. Table 3 shows SID values of solvent extracted CM (SECM) and expeller extracted CM (EECM) fed to growing pigs as reported by Woyengo et al. [96], Maison and Stein [50], Seneviratne et al. [79] and Sanjayan et al. [75]. Energy source
One of the main factors that limit the nutritive value of CM is its low digestibility of energy which is a reflection of its high crude fibre content [88]. Compared to soybean, canola contains a higher amount of oil with many cultivars containing between 40 and 45 % oil on a dry matter basis [32]. The energy content of CM can differ between samples obtained from different crushing plants due to the oil extraction process, i. e. expelled CM contains residual oil at average levels of 9.7 %, compared to 3.2 % for the pre-press solvent extracted meal [65]. The oil content of the meal from the pre-press solvent extraction process would also be affected by the amount of gums added back to the meal following oil refining. As
Page 4 of 13
indicated by Bell [12], gums may contain about 50 % of canola oil and such oil is expected to increase the ME values of the meal. Theodoridou and Yu [91] evaluated the effect of processing conditions on the nutritive value of canola meal and reported significant differences between CM from black- and yellow-seeded B. napus for the basic nutrients, except ash. The differences between yellow and black canola included NDF, ADF, CP, and condensed tannins. Yellow-seeded CM showed higher values for CP, total digestible CP, and lower fiber content [12, 82]. The differences between CM from different cultivars of canola are illustrated in Table 1. Sucrose content for yellow seeded B. napus was higher, and averaged 8.4 %, while the mean values for B. juncea and B. napus black were 6.3 and 7.6 %, respectively. In the case of nonstarch polysaccharides, yellow-seeded B. napus reported higher values and averaged 21.1 %, whereas values for B. juncea and B. napus black averaged 19.4 and 17.0 %, respectively. Total dietary fiber was lower in B. juncea CM, and averaged 25.5 %; 27.1 % for yellow-seeded B. napus whereas B. napus black had 30.1 %. In the case of expelled meal which contains an average 10.0 % of ether extract, the values reported for GE, DE, ME and NE averaged 4873, 3779, 3540 and 2351 kcal/kg, respectively. For pre-press solvent extracted CM, which contains less ether extract (3.2 % on average), the values average 4332, 3273, 3013 and 1890 kcal/kg, respectively [65]; whereas the values for yellow seeded B. napus averaged 3.965, 3248, 3009, and 2102 kcal/kg, respectively; the values for yellow B. juncea averaged 4037, 3392, 3224 and 2340 kcal/kg, respectively [38]. Dehulling of canola can result in a higher energy meal, as shown by research on tail end dehulling of pre-press solvent extracted CM from black and yellow seeded B. napus and canola quality B. juncea; dehulling resulted in low fiber high protein fractions Fine 1 and Fine 2. Compared to their parent meals, the content of total dietary fiber in the fractions decreased from 30.1 to 21.4 and 26.7 % for conventional CM, from 25.5 to 15.3 and 18.7 for yellow-seeded CM, and from 27.1 to 21.6 and 23.4 for B. juncea meal, respectively [56]. The complete removal of the hulls of canola would result in high protein-high energy meal with 47.8 % protein, 10.8 % NDF, 6.6 ADF. [25]. Vitamins and minerals source
Canola meal is a rich source of most of the minerals [12]. Compared to soybean meal, CM has relatively high amounts of Ca, P, S, Mg, Mn and Se, but K and Cu contents are lower Table 4 shows the chemical composition of CM compared to soybean meal [12, 40, 80]; such values are in accordance with National Research Council. Nutrient requirements of swine. 11th Rev. Ed et al.
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Table 4 Chemical composition of canola meal compared to soybean meal Components
Canola meal
Soybean meal
Dry matter, %
90.0
90.0
Crude protein, %
36.5
45.6
Ether extract, %
3.6
1.3
Gross energy, MJ/kg
18.6
20.1
Starch
2.5
0.7
Sucrose
6.0
6.2
Sugar
7.7
6.9
Oligosaccharide
2.5
5.3
Crude fibre
11.6
5.4
Non-starch polysaccharide
18.0
17.8
Neutral detergent fibre
26.0
12.0
Acid detergent fibre
18.2
7.5
Total dietary fibre
31.7
21.8
Arginine
2.04
3.23
Lysine
2.00
2.86
Threonine
1.57
1.74
Methionine
0.74
0.65
Cysteine
0.85
0.67
Tryptophan
0.48
0.64
Calcium
0.7
0.3
Phosphorus
1.2
0.7
Magnesium
0.6
0.3
Sodium
0.08
0.01
Potassium
1.29
2.0
1.0
0.3
Carbohydrates, %
Fibre, %
Amino acids, %
Minerals, %
Vitamins, mg/kg Biotin Folic acid
2.3
1.3
Niacin
169.5
29.0
Pantothenic acid
9.5
16.0
Riboflavin
3.7
2.9
Thiamine
5.2
4.5
Bell [12], Simbaya [80], Khajali and Slominski [40]
[65], However, the presence of phytic acid and high fibre in the meal reduces the availability of most of the minerals. Although the availability of most of the minerals is low in CM, it has high amounts of available Ca, Mg and P compared to soybean meal as shown in Table 4. Canola meal contains considerably high amount of phytatebound phosphorus in proportion to total phosphorus and which ranges from 36 % to over 70 % [40]. Due to
Page 5 of 13
this reason bioavailability of phosphorus has been estimated to be around 30 to 50 % of the total phosphorus in CM [35]. Compared to SBM, CM is a richer source of vitamins such as biotin, niacin, choline, thiamin, Vitamin B6 and niacin. However, pantothenic acid content is lower in CM [28, 65]. Factors affecting feeding and nutritive value of canola meal for swine
There are several factors that limit the use of CM, especially in monogastric animal nutrition. When compared with SBM, CM contains higher contents of dietary fiber, glucosinolates, sinapine, phytic acid, phenolic components such as tannins, lower metabolizable energy, with less consistent AA digestibility and less than optimum electrolyte balance due to high sulfur and low potassium contents [40]. Among these, fibre, glucosinolates, phytic acid and and sinapine are considered to be the main antinutritional factors in CM. Fibre
Fiber content in CM is 3 times higher than SBM [12], which is the result of a large proportion of hulls relative to seed size. The hull represents 16.8 % to 21.2 % of the seed mass [25], but increases to about 30 % of the meal weight after oil extraction, which is the main reservoir for non-starch polysaccharides (NSP) and lignin. Low levels of DE and ME in CM is due to the high level of fiber [12]. High protein soy and 44 % soy with hulls added back contain around 4 % and 7.5 % fibre, respectively, whereas CM has more than 10 % crude fibre [32]. CM contains cellulose (4-6 %), non-cellulosic polysaccharide (13-16 %), lignin and polyphenols (5-8 %) and proteins and minerals associated with the fibre fraction as the major fibre components [81]. Previous studies demonstrated that yellow-seeded meal has low amount of fibre compared to black-seeded meal. For instance, ADF and NDF contents of B. juncea (9.7 % and 15.9 %) are lower compared to those (17.0 % and 23.6 %) of B. napus black as shown in Table 1 [56]. Fibre mainly contains NSP, lignin associated with polyphenols, polyphenol glycoproteins and minerals associated with fibre [80]. Non-starch polysaccharide components of CM are shown in Table 5. Pectic polysaccharidies are present in CM as a non-cellulosic polysaccharide, which is indicated by the presence of uronic acid [81]. Arabinose, xylose, galactose and rhamnose are the main components of galacturonic acid. Part of the arabinose and galactose were derived from arabinan and/or arabinogalactan. Presence of xylose indicates the presence of xylan and xyloglucans. Xyloglucans contain xylose, glucose, galactose and fucose [81]. Cellulose, arabinose, arabinogalactan and pectins are the major NSP components in CM [41,
Mejicanos et al. Journal of Animal Science and Technology (2016) 58:7
Table 5 Non-starch polysaccharides components of canola meal (mg/g) Black B. napus
Yellow B. juncea
Yellow B. napus
Rhamnose
1.2
1.2
1.0
Fucose
1.0
0.8
0.8
Component
Arabinose
22.9
24.1
24.8
Xylose
9.1
7.5
10.3
Mannose
2.6
1.5
2.1
Galactose
7.9
7.7
8.8
Glucose
29.6
27.6
27.2
Uronic acids
26.6
30.4
26.5
Adapted from [82]
59, 81]. In the study by Meng and Slominski [58] it was reported that CM contained 174.5 mg/g total NSP of which 14.3 mg/g was water soluble. Glucosinolates
Glucosinolates (GLS) are sulphur-containing secondary plant metabolites found mainly in the order Capparales known also as Brassicales, which contain plants of the family Brassicaceae that includes the genus Brassica (rapeseed, mustard, and cabbage) [27, 40]. Intact GLS do not cause any harmful effects to animals, however, the break down products of GLS either by enzyme myrosinase or by non-enzymatic factors such as heat, low pH, anatomical and physiological structure of the gastrointestinal tract, digesta transit time and microbial activity cause harmful effects to animals [12]. Depending on the nature of GLS, reaction condition and concentration, the break down products- thiocyanate, isothiocyanate, oxazolidinethione (goitrin) and nitriles may be formed and impair not only feed intake (due to their bitter taste) and growth performance but also affect thyroid function by inhibiting thyroid hormone production and impair liver and kidney function [12, 20, 61]. Previous studies show that growing pigs can tolerate a maximum of 2.02.5 μmol/g of glucosinolates in the diet [12, 74, 77].
Page 6 of 13
Glucosinolates are considered an anti-nutritional factor present in CM. Rapeseed meal contained 110150 μmol/g of GLS [12]. However, through plant breeding techniques new canola varieties have been developed with low level of GLS (
